Conventional approaches for photovoltaic maximum power point tracking (PV MPPT) design based on rule-of-thumb assumptions might not result in the optimal performance in the field. To improve the field performance of practical MPPT designs, this paper proposes a comprehensive approach to MPPT design driven by experimentally measured field data. The data on the dynamic behavior of PV panel I-V characteristics has been collected over a long period at a significantly higher rate than previously reported in the literature. This paper presents the measurement setup, the collected data and most importantly its design applications. The P&O method has been taken as an example to illustrate how this data can be applied to optimize a practical MPPT design in terms of tracking speed and efficiency.